Ozone oxidation catalyst, preparation method and ozone catalytic oxidation device
Technical Field
The application relates to the field of sewage ozone catalytic oxidation treatment, in particular to an ozone oxidation catalyst, a preparation method and an ozone catalytic oxidation device.
Background
The ozone oxidation treatment method of waste water is a method for purifying and disinfecting waste water by using ozone as oxidant. The existing ozone oxidation treatment can be combined with other technologies for application, so that the water treatment effect is improved.
For example, the metal-catalyzed ozone oxidation technology commonly used in the existing ozone combined treatment uses solid metal (metal salt and oxide thereof) as a catalyst, thereby enhancing the ozone oxidation reaction. The metal-catalyzed ozone oxidation is a novel technology developed in recent years, and at present, a catalyst carrier is mostly soaked in a catalyst impregnation liquid, and metal (or metal salt or metal oxide) is dissolved or dispersed in the catalyst impregnation liquid, so that the metal (or metal salt or metal oxide) is loaded on the catalyst carrier in the impregnation process, and then the catalyst is obtained after solidification treatment.
The catalyst of the existing ozone oxidation catalyst uses alumina porous microspheres, active carbon or diatomite, the inside of the catalyst has a plurality of fine pores, the specific surface area is large, and the catalytic area of the prepared catalyst is large. However, due to the fine pores on the catalyst carrier, the catalyst carrier is difficult to impregnate and permeate in the existing impregnation method, so that the catalytic loading efficiency is low, the existing loading time is 24-72 hours, the loading depth is poor, and the loading of the central area of the catalyst carrier is less.
Disclosure of Invention
In order to improve the impregnation efficiency and effect of the catalyst, the application provides an ozone oxidation catalyst, a preparation method and an ozone catalytic oxidation device.
In a first aspect, the present application provides a method for preparing an ozone oxidation catalyst, which employs the following technical scheme:
a preparation method of an ozone oxidation catalyst comprises the following steps,
s1: soaking a catalyst porous carrier into dichloromethane sufficiently to obtain a treated porous carrier, wherein the catalyst porous carrier is one or a mixture of porous activated alumina and porous activated carbon;
s2: carrying out pressurized injection and pressure treatment on a porous carrier by using a catalyst impregnation solution to replace dichloromethane, wherein the liquid pressure is 0.8-1.6 MPa, and the replacement time is 40-60min, so as to obtain an impregnated porous carrier, the catalyst impregnation solution takes water as a main solvent, the water accounts for more than 85wt% of the solvent, the catalyst impregnation solution contains catalytic metal ions, and the catalytic metal ions are one or more of copper ions, cerium ions and manganese ions;
s3: immersing the impregnated porous carrier into an alkaline liquid environment, and obtaining a loaded porous carrier after the impregnated porous carrier catalyzes metal ions to convert and precipitate;
s4: and heating and burning the loaded porous carrier, wherein the highest burning temperature is 600-800 ℃, burning until the loaded porous carrier precipitates and converts the oxide, and cooling to room temperature to obtain the porous catalyst.
By adopting the technical scheme, the catalyst porous carrier is filled with the dichloromethane with low boiling point and strong permeability, the catalyst impregnation liquid with water as a main solvent utilizes the density difference and the difference driven by liquid flow, so that the dichloromethane is rapidly replaced by the catalyst impregnation liquid, the rapid penetration of the catalyst impregnation liquid to the porous carrier is completed, the penetration is rapid and complete, finally, trace residual dichloromethane escapes in the heating process before firing, holes blocked by sediment on the surface part of the catalyst are dredged, and finally, the production efficiency of the catalyst and the catalytic effect of a finished catalyst are improved.
Preferably, the catalyst porous carrier is one of porous activated alumina and porous activated carbon.
Through adopting above-mentioned technical scheme, the structure design of porous active alumina and porous active carbon is convenient, and has certain structural strength, when catalyst impregnation liquid replaces dichloromethane, can guarantee that the hole in the porous carrier of catalyst can not destroy shutoff etc. because of pressure variation, guarantees that dichloromethane is pressed soon by catalyst impregnation liquid overstocking outflow, and catalyst production efficiency can further improve.
Preferably, methylene chloride is replaced by pressure-injection-treating the porous support with a catalyst impregnation solution flowing to wash-treat the porous support in S2.
By adopting the technical scheme, the catalyst impregnation liquid flows and washes the porous carrier, so that the catalyst impregnation liquid is accelerated to replace dichloromethane, the impregnation and permeation efficiency is accelerated, and the catalyst preparation efficiency and the catalyst finished product quality are further improved.
Preferably, the particle size of the catalyst porous carrier is 1-2 cm, and the flow velocity of the catalyst dipping solution is 0.3-0.5 m/s.
By adopting the technical scheme, the obtained catalyst has good loading effect.
Preferably, the porous carrier is washed from bottom to top by flowing the catalyst impregnation solution to wash the porous carrier.
By adopting the technical scheme, the applicant thinks that the dichloromethane density difference can accelerate the replacement rate of the catalyst impregnation liquid, and meanwhile, the porous carrier with the higher catalyst impregnation liquid replacement rate is subjected to smaller buoyancy force and lower buoyancy force than the porous carrier with the lower replacement rate, so that the possibility that the replaced dichloromethane is adsorbed by the porous catalyst again is reduced, and the porous carrier with the higher catalyst impregnation liquid replacement rate is subjected to larger impact force, thereby being beneficial to complete dichloromethane replacement.
Preferably, the burning temperature rise process in S4 includes the following three stages:
t1: heating from room temperature to 35-39 deg.C for 20-30min,
t2: heating to 200 deg.C from T1, and heating for 10 min;
t2: heating to the maximum temperature from T1 for 40-60 min.
By adopting the technical scheme, the temperature is increased in a stepped manner, dichloromethane is removed at the stage of 35-39 ℃, most of free water is removed at the stage of 200 ℃, and then a certain product catalytic effect is improved by burning. The applicant believes that trace dichloromethane possibly remaining in the porous carrier in the T1 stage is removed from the porous carrier through heating evaporation, so that adverse effects of dichloromethane residue on subsequent heating are avoided, and the trace dichloromethane diffuses along holes of the porous carrier when removed on the other hand, so that some blocked holes in the porous carrier are dredged, the blocking of the holes is reduced, and the specific surface area of the catalyst is increased.
Preferably, the firing after T2, T3 and T3 in S4 is a vacuum environment.
By adopting the technical scheme, the moisture in the porous carrier is completely removed, the ignition is more complete, and when the porous catalyst is activated carbon fire or other objects which are easy to react with air at high temperature, the reaction can be reduced.
In a second aspect, the present application provides an ozone oxidation catalyst that employs the following technical solutions:
an ozone oxidation catalyst obtained by the preparation of the ozone oxidation catalyst.
By adopting the technical scheme, the catalytic efficiency of the catalyst is greatly improved, the efficient treatment of sewage in batches is facilitated, and the sewage treatment effect is improved.
In a third aspect, the present application provides an ozone catalytic oxidation apparatus, which adopts the following technical scheme:
the catalytic ozonation device comprises a treatment chamber for mixed flow of sewage and ozone, wherein the treatment chamber is filled with the ozone oxidation catalyst.
Through adopting above-mentioned technical scheme, catalyst change cycle when reducing sewage treatment improves sewage treatment effect from this.
In summary, the present application has the following beneficial effects:
1. the catalytic efficiency of the ozone oxidation catalyst is greatly improved, and the ozone oxidation catalyst is beneficial to efficient treatment of sewage in batches;
2. the catalyst porous carrier is quickly infiltrated and filled with dichloromethane, and then the catalyst impregnation liquid is used for quickly replacing the dichloromethane by utilizing the density difference and the liquid flow driving difference, so that the quick infiltration of the catalyst impregnation liquid on the porous carrier is completed, the infiltration is quick and complete, and the production efficiency of the catalyst and the catalytic effect of a finished catalyst product are finally improved;
3. the porous carrier is washed from bottom to top by flowing the catalyst impregnation solution, the replacement rate of the catalyst impregnation solution is accelerated by utilizing the density difference of dichloromethane, on one hand, the possibility that the replaced dichloromethane is adsorbed by the porous catalyst again is reduced, on the other hand, the porous carrier with higher catalyst impregnation solution replacement rate sinks, so that the impact is larger, and the complete replacement of the dichloromethane is facilitated;
4. the trace dichloromethane possibly remaining in the porous carrier is removed from the porous carrier by heating evaporation, so that the adverse effect of dichloromethane residue on subsequent heating is avoided, and the holes blocked in the porous carrier are dredged when the trace dichloromethane is removed on the other side, so that the multi-hole blocking is reduced, and the catalytic specific surface area is increased.
Drawings
FIG. 1 is a catalyst preparation system of example 1;
FIG. 2 is a catalyst preparation system of example 8;
FIG. 3 is the catalytic ozonation unit of example 15;
figure 4 is the embodiment of the ozone catalytic oxidation device 16.
Reference numerals: 1. a liquid storage unit; 2. a circulation unit; 11. a reservoir; 21. a liquid outlet pipeline; 22. a circulation line; 23. a filling container; 24. a circulation pump; 3. a catalytic tube; 31. a sewage inlet; 32. a treatment outlet; 33. a sieve plate; 34. a processing chamber; 4. an ozone access pipe; 5. a gas distributor; 51. a shunt folded plate; 6. a fixed bed reactor; 61. an outer housing; 62. fixing a bed layer; 7. a sewage inlet pipe; 8. and a material discharge pipe.
Detailed Description
In the case of the example 1, the following examples are given,
an ozone oxidation catalyst is prepared by using gamma-alumina porous pellets as a porous carrier and using a mixed solution of manganese chloride and cerium chloride as a catalyst impregnation solution. Wherein the porous carrier has a particle diameter of 2 + -0.2 cm and an apparent density of 0.4g/cm3. The manganese ion concentration in the catalyst impregnation liquid is 0.5mol/L, and the cerium ion concentration is 0.8 mol/L.
As shown in fig. 1, the catalyst preparation system used in the ozone catalyst preparation process of the present application comprises a storage unit 1 and a circulation unit 2, wherein the storage unit 1 comprises a storage container 11, and the storage container 11 can be sized according to the single catalyst preparation amount, which is 1m 2 m.
The circulation unit 2 comprises a liquid outlet line 21, a circulation line 22, a filling vessel 23 and a circulation pump 24.
The liquid outlet pipe 21 is connected to the bottom of the liquid storage container 11 at one end and to the bottom of the filling container 23 at the other end.
The circulation line 22 is connected to the circulation pipe at the top of the reservoir 11 and the other end is connected to the top of the filler 23.
The circulating pump 24 is installed in the liquid outlet pipe 21, and after the circulating pump 24 is started, the catalyst impregnation liquid can be pumped from the bottom of the liquid storage container 11 and pumped out from the other end of the liquid outlet pipe 21 into the filling container 23, and then circulated back into the liquid storage container 11 through the circulating pipe.
The packing container 23 is a round tube, here a transparent tube, the size of which is determined by the single catalyst preparation, here a transparent tube with an inner diameter of 8cm and a length of 20cm, the packing height of the porous support is 10cm, the packing container 23 is closed at both ends with screens, and the mesh of the screens is 1cm x 1 cm.
The preparation method of the ozone oxidation catalyst comprises the following steps:
s1: completely immersing the porous carrier into dichloromethane for 40min to obtain a treated porous carrier;
s2: filling the porous carrier to be treated into a filling container, wherein the filling height of the porous carrier to be treated is 10cm, connecting the filling container into a catalyst preparation system, starting a circulating pump, controlling the circulating flow rate to be 0.4m/s, the liquid pressure to be 1MPa, and the circulating time to be 30min, and obtaining the impregnated porous carrier after the circulation is finished;
s3: soaking the obtained impregnated porous carrier into 1.3mol/L sodium hydroxide solution for 24 hours to obtain a loaded porous carrier;
s4: heating and burning the loaded porous carrier,
t1: heating from room temperature to 38 deg.C for 25min,
t2: transferring to a vacuum environment after T1 is finished, wherein the vacuum degree is 0.1MPa, heating to 200 ℃, and heating for 10 min;
t3: maintaining the vacuum environment from T2 with the vacuum degree of 0.1MPa, heating to 700 deg.C, and heating for 52 min;
t4: and (3) after the porous carrier is loaded to precipitate and convert the oxide, cooling to room temperature to obtain the porous catalyst.
Examples 2-5, based on example 1, experimental modifications were made to the process parameters to obtain the porous catalysts of examples 2-5.
Specific process parameters for examples 1-5 are shown in table one below.
TABLE 1 detailed Process parameters for examples 1-5
In the comparative example 1,
an ozone oxidation catalyst is prepared by using gamma-alumina porous pellets as a porous carrier and using a mixed solution of manganese chloride and cerium chloride as a catalyst impregnation solution. Wherein the porous carrier has a particle diameter of 2 + -0.2 cm and an apparent density of 0.4g/cm3. The manganese ion concentration in the catalyst impregnation liquid is 0.5mol/L, and the cerium ion concentration is 0.8 mol/L.
The preparation method comprises the following steps:
s1: filling a porous carrier into a filling container, wherein the filling height of the porous carrier is 10cm, connecting the filling container into a catalyst preparation system, starting a circulating pump, controlling the circulating flow rate to be 0.4m/s, the liquid pressure to be 1MPa, and the circulating time to be 30min, and obtaining the impregnated porous carrier after the circulation is finished;
s3: soaking the obtained impregnated porous carrier into 1.3mol/L sodium hydroxide solution for 24 hours to obtain a loaded porous carrier;
s4: heating and burning the loaded porous carrier,
t1: heating from room temperature to 38 deg.C for 25min,
t2: transferring to a vacuum environment after T1 is finished, wherein the vacuum degree is 0.1MPa, heating to 200 ℃, and heating for 10 min;
t3: maintaining the vacuum environment from T2 with the vacuum degree of 0.1MPa, heating to 700 deg.C, and heating for 52 min;
t4: and (3) after the porous carrier is loaded to precipitate and convert the oxide, cooling to room temperature to obtain the porous catalyst.
Comparative example 2, an ozone oxidation catalyst was prepared using gamma-alumina porous beads as a porous carrier and a mixed solution of manganese chloride and cerium chloride as a catalyst impregnation solution. Wherein the particle size of the porous carrier is 2 + -0.2 cmApparent density of 0.4g/cm3. The manganese ion concentration in the catalyst impregnation liquid is 0.5mol/L, and the cerium ion concentration is 0.8 mol/L.
The preparation method comprises the following steps:
s1, soaking the porous carrier into the catalyst soaking solution for 40min to obtain a soaked porous carrier;
s2: heating and burning the loaded porous carrier,
t1: heating from room temperature to 38 deg.C for 25min,
t2: transferring to a vacuum environment after T1 is finished, wherein the vacuum degree is 0.1MPa, heating to 200 ℃, and heating for 10 min;
t3: maintaining the vacuum environment from T2 with the vacuum degree of 0.1MPa, heating to 700 deg.C, and heating for 52 min;
t4: and (3) after the porous carrier is loaded to precipitate and convert the oxide, cooling to room temperature to obtain the porous catalyst.
Comparative example 3, an ozone oxidation catalyst, based on comparative example 2, is distinguished in that the porous carrier is soaked in the catalyst soak for 70 min.
Comparative example 4, an ozone oxidation catalyst, based on comparative example 2, is distinguished in that the porous carrier is soaked in the catalyst soak for 24 hours.
Comparative example 5, an ozone oxidation catalyst, based on comparative example 2, is distinguished in that the porous carrier is soaked in the catalyst soak for 38 hours.
In the case of the example 6, it is shown,
an ozone oxidation catalyst based on example 1, wherein S2 of example 6 is different from S2 of example 1 in the preparation method, and S2 of example 6 is as follows:
pouring the treated porous carrier into a container, adding a catalyst impregnation liquid, sealing the container, pressurizing to 1MPa, slowly shaking the container to enable the liquid inside to flow, opening the container after slowly shaking for 60min, and taking out to obtain the impregnated porous carrier, wherein the catalyst impregnation liquid is higher than the catalyst impregnation liquid by 10 cm.
In the case of the example 7, the following examples are given,
an ozone oxidation catalyst based on example 1 was distinguished by experimental attempts at different catalyst impregnation solution flow rates.
The catalyst impregnation solution flow rates were as follows:
|
example 7A
|
Example 7B
|
Example 7C
|
Flow rate m/s of catalyst impregnation solution
|
0.2
|
0.3
|
0.5 |
In the case of the example 8, the following examples are given,
an ozone oxidation catalyst based on example 1, which is different from the above catalyst in that the connection manner of the pipelines in the catalyst preparation system is changed.
As shown in FIG. 2, the circulation line 22 of the catalyst preparation system of example 8 has one end connected to the circulation pipe at the top of the storage vessel 11 and the other end connected to the bottom of the charging vessel 23.
The outlet line 21 is connected at one end to the bottom of the reservoir 11 and at the other end to the top of the filler 23.
The catalyst impregnation liquid washes the impregnated porous carrier from top to bottom, and the circulating pump 24 is adjusted to keep the flow rate at 0.4m/s and the hydraulic pressure at 1 MPa.
In the case of the example 9, the following examples are given,
an ozone oxidation catalyst based on example 1, which is different from example 1 in S4 in example 9 and S4 in example 1 in the preparation method, wherein S4 in example 9 is as follows:
heating to 700 deg.C in vacuum environment with vacuum degree of 0.1MPa, heating for 52min, precipitating and converting oxide on the supported porous carrier, and cooling to room temperature to obtain porous catalyst.
Example 10, an ozone oxidation catalyst, based on example 1, differs from example 1 in that the preparation method of S4 in example 10 is different from S4 in example 1, and S4 in example 10 is burned under normal pressure.
Example 11, an ozone oxidation catalyst, based on example 1, was distinguished by the experimental attempts to use different catalyst impregnation solution hydraulics.
The catalyst impregnation solution flow rates were as follows:
|
example 11A
|
Example 11B
|
Example 11C
|
Catalyst impregnation solution hydraulic pressure MPa
|
0.8
|
1.6
|
1.8 |
Example 12 an ozone Oxidation catalystThe catalyst was prepared by using porous activated carbon as a porous carrier and a mixed solution of manganese chloride and cerium chloride as a catalyst impregnation solution, based on example 1. Wherein the porous carrier has a particle diameter of 1 + -0.2 cm and an apparent density of 0.32g/cm3. The manganese ion concentration in the catalyst impregnation liquid is 0.5mol/L, and the cerium ion concentration is 0.8 mol/L.
Example 13 is an ozone oxidation catalyst based on example 1, and is different in that a catalyst is prepared by using porous activated carbon as a porous carrier and a mixed solution of copper chloride as a catalyst impregnation solution. Wherein the porous carrier has a particle diameter of 1 + -0.2 cm and an apparent density of 0.32g/cm3. The concentration of copper ions in the catalyst impregnation liquid was 1.2 mol/L.
Example 14, based on example 1, an ozone oxidation catalyst, which was prepared using a mixed solution of copper chloride as a catalyst impregnation solution, was different. The concentration of copper ions in the catalyst impregnation liquid is 1.5 mol/L.
The catalysts obtained in examples 1 to 14 and comparative examples 1 to 4 were tested for their ozone catalytic oxidation performance.
[ ozone catalytic Oxidation Performance test ]
The method comprises the steps of obtaining test raw water after filtering organic wastewater, taking 500ml of the test raw water, measuring the COD value (here, 90mg/L) of the test raw water, taking 900ml of the test raw water, putting the test raw water into a container with a volume mark (a cylinder with the inner diameter of 8), adding a catalyst with the volume of 400ml, blowing ozone from the bottom, carrying out catalytic oxidation, grouping each group of catalyst samples for a plurality of groups of different catalytic oxidation time, and setting an experiment for directly introducing the ozone without using the catalyst as a blank example. The results are expressed as the removal rate.
The results of the catalytic efficiency test are shown in the following table.
TABLE II catalytic efficiency test result table
Catalysis time/min
|
Example 1
|
Example 2
|
Example 3
|
Example 4
|
Example 5
|
|
0
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
|
10
|
59.63%
|
58.98%
|
59.23%
|
59.03%
|
59.11%
|
|
20
|
90.83%
|
89.76%
|
90.51%
|
90.11%
|
89.87%
|
|
30
|
93.58%
|
92.95%
|
93.12%
|
92.67%
|
93.39%
|
|
Catalysis time/min
|
Comparative example 1
|
Comparative example 2
|
Comparative example 3
|
Comparative example 4
|
Comparative example 5
|
Blank example
|
0
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
10
|
39.80%
|
29.24%
|
31.36%
|
59.12%
|
59.87%
|
26.58%
|
20
|
59.70%
|
44.60%
|
47.92%
|
90.11%
|
91.00%
|
40.51%
|
30
|
67.16%
|
56.99%
|
60.98%
|
93.10%
|
93.68%
|
51.90%
|
Catalysis time/min
|
Example 6
|
Example 7A
|
Example 7B
|
Example 7C
|
Example 8
|
Example 9
|
0
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
10
|
47.07%
|
54.67%
|
59.15%
|
59.68%
|
53.02%
|
53.21%
|
20
|
71.25%
|
79.00%
|
90.47%
|
90.87%
|
75.49%
|
87.57%
|
30
|
83.54%
|
89.63%
|
93.39%
|
93.60%
|
87.57%
|
91.21%
|
Catalysis time/min
|
Example 10
|
Example 11A
|
Example 11B
|
Example 11C
|
Example 12
|
Example 14
|
0
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
0.00%
|
10
|
56.17%
|
59.58%
|
59.68%
|
59.68%
|
53.35%
|
50.38%
|
20
|
86.83%
|
90.81%
|
90.87%
|
90.88%
|
76.37%
|
68.22%
|
30
|
89.84%
|
93.51%
|
93.60%
|
93.64%
|
89.58%
|
80.30% |
Combining examples 1-5, comparative examples 1-3, blank and combining table 2, it can be seen that the catalytic efficiencies (removal rates) of examples 1-5 are better than those of comparative examples 1-3 and blank at the same catalytic time.
Meanwhile, the removal rate of the examples 1-5 is obviously reduced along with the increase of time at the later stage when the removal rate is close to 90%, the removal rate of the comparative examples 1-3 is obviously reduced along with the increase of time after the removal rate exceeds 60%, the limit value of the removal rate of the examples 1-5 is far larger than that of the comparative examples 1-3, and the limit value of the removal rate of the examples 1-5 (larger than 90%) is nearly reached at about 30min and is far higher than that of the comparative examples 1-3 (58-70%).
Therefore, the preparation method for replacing the quickly-permeated and filled catalyst porous carrier with the dichloromethane can effectively and quickly enable the catalyst impregnation liquid to permeate the porous carrier in a short time, and the catalyst impregnation liquid can completely permeate the porous carrier, so that the catalytic effect of the finished catalyst product is achieved.
Combining examples 1-5, comparative examples 3-4 and table 2, it can be seen that the same or similar catalytic efficiency (removal rate) as that of the present application can be obtained by the existing impregnation method, but the impregnation time of the catalyst impregnation liquid in the preparation process needs 24-38h, while the sum of the impregnation time of examples 1-5 and the replacement time of the catalyst impregnation liquid is 1-2h, which is far less than the impregnation time, so that the preparation method of quickly permeating and filling the catalyst porous carrier with dichloromethane for replacement in the present application can be seen to improve the production efficiency of the catalyst.
It can be seen from the combination of example 1 and example 6 and the combination of table 2 that the catalyst impregnation liquid flows to wash the porous carrier, so that the catalyst impregnation liquid can be accelerated to replace dichloromethane, the impregnation and permeation efficiency can be accelerated, and the catalyst preparation efficiency and the catalyst finished product quality can be further improved.
It can be seen from the combination of the embodiment 1 and the embodiment 7 and the table 2 that the flow rate of the catalyst impregnation solution is 0.3-0.5 m/s, so that the obtained catalyst has a good loading effect, the replacement effect is reduced due to too low flow rate, the replacement effect is not greatly improved due to too high flow rate, but the energy consumption is increased, and the damage to the porous carrier of the catalyst may be caused due to too high flow rate.
It can be seen from the combination of example 1 and example 8 and the combination of table 2 that the catalytic efficiency of the catalyst prepared by the bottom-up washing of the porous carrier by the flowing washing of the catalyst impregnation solution is better than that of the top-down washing, and the applicant believes that the density difference of dichloromethane can accelerate the replacement rate of the catalyst impregnation solution, and the porous carrier with the higher replacement rate of the catalyst impregnation solution is subjected to smaller buoyancy and lower buoyancy than the porous carrier with the lower replacement rate, so that the possibility that the replaced dichloromethane is adsorbed by the porous catalyst again is reduced, and the porous carrier with the higher replacement rate of the catalyst impregnation solution is subjected to larger impact, which is beneficial to the complete replacement of dichloromethane.
Combining the embodiment 1 and the embodiment 9 and combining the table 2, it can be seen that the catalytic efficiency of the embodiment 1 is better than that of the embodiment 9, the application adopts the step temperature rise, dichloromethane is removed at the stage of 35-39 ℃, most of free water is removed at the stage of 200 ℃, and then the burning can improve certain catalytic effect of the product.
Combining example 1, example 10 and table 2, it can be seen that the catalytic efficiency of example 1 is better than that of example 10, and the application makes the burning after T2, T3 and T3 in S4 to be vacuum environment, which can make the moisture in the porous carrier completely removed and the burning more complete. And when the porous catalyst is activated carbon fire or other objects which are easy to react with air at high temperature, the reaction can be reduced.
It can be seen from the combination of examples 12-14 and table 2 that the present application can also be adapted to the preparation of catalysts by using catalyst impregnation solutions of other different metal ions and porous activated carbon as a catalyst carrier.
Example 15, an ozone catalytic oxidation unit, which is a compact catalytic oxidation unit, includes a catalytic tube 3. The catalytic tube 3 comprises a sewage inlet 31 and a treatment outlet 32 at both ends.
Inside the setting of catalytic tube 3 has two sieve 33 along the axial, and inside two sieve 33 separated catalytic tube 3, formed treatment chamber 34 between sieve 33, the ozone oxidation catalyst of this application is filled in treatment chamber 34.
The side surface between the sewage inlet 31 of the catalytic tube 3 and the close sieve plate 33 is connected with an ozone access tube 4, and the ozone access tube 4 is connected with an ozone source with band pressure.
Meanwhile, a gas distributor 5 is arranged at the corresponding position of the connection part of the ozone access pipe 4 along the axial direction of the catalytic pipe 3. The gas distributor 5 distributes the ozone introduced into the catalytic tube 3, so that the mixing degree of the ozone and the sewage is improved. The gas distributor 5 can be selected from the prior art according to the actual situation, where the gas distributor 5 comprises a diverter flap 51.
The diversion flap 51 is in a strip shape, and the length direction thereof is parallel to the axis of the catalytic tube 3. The shunt flap 51 is folded and protruded towards the ozone access pipe 4 in the direction towards one side of the connection part of the ozone access pipe 4, the cross section of the shunt flap 51 perpendicular to the length direction is V-shaped, and the tip end of the ozone access pipe 4.
The number of the shunt folding plates 51 can be determined according to the actual situation, and here, the shunt folding plates 51 are multiple, and are distributed less on the side of the catalytic tube 3 close to the ozone access tube 4, and are distributed more on the side of the catalytic tube 3 far away from the ozone access tube 4.
Embodiment 16, an ozone catalytic oxidation device, it is large-scale catalytic oxidation device, including fixed bed reactor 6, fixed bed reactor 6 includes shell body 61 and fixes the fixed bed 62 in shell body 61, and the ozone oxidation catalyst of this application is packed in the fixed bed 62.
The bottom of the fixed bed reactor 6 is connected with an ozone access pipe 4 and a sewage inlet pipe 7, and the top of the fixed bed reactor 6 is connected with a material discharge pipe 8.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.